CONWAY – With another day passed since 15-year-old Abigail Hernandez was last seen, authorities are now publicly expressing worry about what may have happened to her.

"It's now 10 days. We have significant fears about her safety," said Kieran L. Ramsey, an FBI special agent from Boston leading the FBI's side of the investigation.

Authorities still have no evidence to indicate that Hernandez was abducted, Ramsey said, and it's still possible that she is alive and well.

"But every day that goes by gives us more worry, because we have no idea if she is safe."

Search crews combed the woods on the west side of Cranmore Mountain Friday looking for Hernandez, her cell phone, and/or clues to her whereabouts.

Hernandez was last seen on Oct. 9 walking home from school at about 2:30 p.m. near the North-Sound Road, which begins near the high school. Investigators said Hernandez' "previous after-school travel pattern" was to walk that road every day along that route to her home at 86 Village Way.

The last time she was heard from, authorities said, was when friend, identified by family members as Hernandez' boyfriend, Jimmy Campbell, received a text from her at about 2:53 p.m. The text was a heart symbol.

Investigators Wednesday asked area residents and businesses to help find the girl's cell phone, a white iPhone in a pink case, which last made contact with a cell tower on Cranmore Mountain at 3:07 p.m.

Authorities announced a $20,000 reward Thursday for any information leading to the identification of Abigail Hernandez, to an arrest in her case, or for any other information that helps authorities find her.

Ramsey said a large number of tips came in Friday, "and I'd like to think some of those were a result of the reward offer, but we haven't investigated them all yet," Ramsey said.

The $20,000 amount, though, will likely rise, he said. The FBI's maximum reward amount for such cases is $20,000, but several residents have come forward with donations to make it larger. One resident wants to donate $5,000 to the reward amount, he said.

"The amount will likely go up, and we thank the people in the community for being so generous," Ramsey said. "The community has been very helpful to us."

Anyone with information about her disappearance is asked to call the Conway Police Department at 356-5717, or the FBI tip line at 1-800-CALL FBI or leave information on line at tips.fbi.gov.